As electronics technologies progress, many different kinds of input devices, such as keyboards, mice, and light pens have been developed. In addition to conventional personal computers, many new electronic devices make use of one or more input devices to input or retrieve data.
As technology progresses, many electronic devices are continually made smaller and smaller. A typical electronic device such as a mobile phone, personal digital assistant (PDA), electronic translator, notebook computer, digital camera, digital recording pen, game console or the like, is typically manufactured in a size that is small enough to be portable and convenient for mobile users. The portability frequently creates problems while users perform input or output operations over the electronic device since many miniaturized input devices are difficult, inconvenient, or uncomfortable to use. Examples of space-saving input devices include light pens, mice, keyboards, drawing pads and the like.
An alternative to a miniaturized input apparatus involves providing an input apparatus separate from the electronic device itself. In other words, the input apparatus becomes a separable peripheral apparatus that connects to the device in operation. For example, a mobile phone or PDA frequently has a separable keyboard or other similar separable peripheral input devices. Even the input apparatus designed to be a separable component, however, is frequently too small for comfortable portable use. An auxiliary input apparatus is desired to overcome the problems mentioned above.